Can't start bugtimetracker on Natty

The following occurs when starting bugtimetracker on my system, I did update to the latest rev available and this did work initially.

sfeole@sfmadmax:~$ bugtimetracker
Traceback (most recent call last):
  File "/usr/bin/bugtimetracker", line 2, in <module>
    import bugtimetracker
  File "/usr/lib/python2.7/dist-packages/bugtimetracker/__init__.py", line 4, in <module>
    from .application import Application
  File "/usr/lib/python2.7/dist-packages/bugtimetracker/application.py", line 12, in <module>
    from . import widget, assistant
  File "/usr/lib/python2.7/dist-packages/bugtimetracker/assistant.py", line 13, in <module>
    from . import launchpad as lp
  File "/usr/lib/python2.7/dist-packages/bugtimetracker/launchpad.py", line 18, in <module>
    import oauth2 as oauth
ImportError: No module named oauth2